Caster



(N0 Model.) 2 Sheets-Sheet 1.

' 1V[.B.'SCHENGK.-

CASTER.

No. 301,835. Patented July 8 1884.

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(No Model.) 2 ShetS- -Sheet 2.

B. SGHENCK.

. I (EASTER. No. 301,835. Patented July 8,- 1884.

' above the axle of the floor-wheels.

INITED STATES ATENT Fries.

MARTIN B. SCHENCK, OF FULTON, NE\V YORK, ASSIGNOR TO THE YALE CASTER COMPANY, OF NEXV HAVEN, CONNECTICUT.

CASTER.

SPECIFICATION forming part of Letters Patent No. 301,835; dated July 8, 188%.

Application filed September 30, 1882. (No model.)

To all whom it may concern:

Be it known that I, MARTIN B. ScHnNoK, a citizen of the United States, residing at Fulton, in thecounty of Oswego and State of New York, have invented certain new and useful Improvements on Casters, of which the following is a specification.

My improvement relates to those casters having two floor-wheels, which are constructed to allow both a horizontal pivoting and a vertical rocking movement to the wheel frame or housing. 'It has been customary to pivot the housingon a central vertical pin in various manners, to allow of the rocking motion of the housing, and to journal an anti-friction wheel in the housing above the floor-wheel axle, in such manner that it will bear on the under side of a track-plate affixed to the furniture .or truck, to receive a portion of the Weight and serve as a rocker-bearing. WVith a caster thus constructed it is essential that the point of contact of the anti-friction wheel be directly If inside of a vertical plane including this axle, a too heavy, or possibly a breaking, strain will be applied to the central pivot-pin, while if without this plane great friction would be caused both at the central pivot and at the tail-piece of the housing, and even with the anti-friction wheel placed directly above the floor-wheel axle great friction and imperfect pivoting are caused by the abutting of this tail-piece against the track-plate, especially when the casterhappens to be pushed the wrong way.

My improvement relates, first, to means of overcoming this difficulty and producing at the same time a practically frictionless and a perfect oscillatory bearing for the wheel-housing. This object I accomplish by placing on one or the other side of the central pivot an additional anti-friction wheel or roller having its axis lying in a vertical plane, in which lie also the first anti-friction roller and the vertical pivot-pin.

My invention relates, secondly, to details of construction of means for accomplishing the result above set out; and, thirdly, to an im proved method of connecting the pivot-pin to the housing by means of an oscillating thimble,

in manner hereinafter more fully set forth,

which portion of my invention is equally applicable to a caster with one as to one with two anti-friction rollers.

In order that my invention may be fullyunderstood, I will proceed to describe it with reference to the accompanying drawings, in which Figure l is a rear elevation of my improved caster. Fig. 2 is a side elevation of the preferred form thereof. Fig. 3 is a vertical longitudinal section of the same on the line. 3 3, Fig. 1. Fig. 4 is a plan with the track-plate removed. Fig. 5 is a section, similar to Fig. 3, 'ofa modification of my invention. Fig. 6 is a plan of the same, with the track-plate removed. Figs. 7 and'8 represent in section other modifications of my invention.

In the drawings, A is a track-plate, having means of attachment beneath a truck or piece of furniture. On the upper side of this plate is a stud or boss, a, extending into a socket in the furniture-leg or truck-bottom. On its lower side'the plate bears a similar stud, a, which may, as shown in Fig. 3, extend low enough to transmit strain from the track-plate to the wheel-frame, or may, as shown in Fig.

7, be made only of sufficient depth to strengthen the central pivot-pin, by which, in this case, the whole of the strain is received and transmitted.

Passing vertically through the center of the studs a a is a screw bolt or in B havin in 7 7 25,

the form of my invention here shown, a conical head, I), which occupies asimilarly-shaped hole in a washer, C. The upper end of pin B is riveted or secured by other suitable means, D, above the stud a, and the washer C is made to bear with friction against the base of the stud a, and serve asa flange to retain the thimble E in place thereon.

It will be readily seen that the form of the head b and of the hole in washer C may be altered, or that the washer maybe altogether-omitted, the head b being in such case fiat and of sufficient width to extend beyond the stud a.

The thimble E. is an oval-shaped casting having avertical circular hole,through which'passes the cylindrical stud a. Down- IOO zontal pin F, which enters also corresponding holes in the housing G, and serves to fasten the same to the thimble, and through it to the track-plate. A flange, 0, on the thimble E, assisted by the washer 0, serves to retain the thiinble upon the stud a, which is made of sufficient depth to allow a slight vertical play to the thinible. The housing G is provided with a recess or basin, for receiving the thimblc E and its appurtenances, and also with slots or recesses g, in the form of my in vention here shown-one on each side of the recess so that the anti-friction wheels H H, contained in said slots,may be both journaled upon the same horizontal pin,F', employed to connect the thimble and housing together. Instead, however, of having the anti-friction wheels 011 opposite sides of the central pivot, they may both be upon the same side; or I may employ a two-faced wheel, as shown in Fig. 8 at H, to give a bearing in two places on two tracks. The anti-friction wheels H H H bear upwardly against a track or tracks, 71, on the under face of the plate A. The housing or wheel-frame G has three brackets or lugs, G, through which passes the axle I of the two floor-wheels .I .T.

It will be observed that the main or all of the weight of the truck or piece of furniture will be carried by the wheels H II, and by them transferred to the housing. I11 this manner a perfect compound rocking and pivotal motion is allowed the caster. \Vhile I have here shown the outer anti-friction wheel, H, almost directly above the floor-wheel axle, yet it may be placed at some distance on either side of the axle without injuring the working of the caster. It is necessary, however, in all cases that the axis of the wheels H H and the vertical pivotal point of the caster shall lie in the same vertical plane, in order to secure a perfect oscillatory motion.

In the form of my invention which I have illustrated in Figs. 5 and 6, the anti-friction wheels H and H run on different tracks on the attaching-plate, the thiinble E is omitted, and the horizontal pin passes directly through the pivot-pin, which turns within the hole in the track-plate, andis held above by screwbolt or by riveting and washer K L.

The following is claimed as new in the abovedeseribed invention:

1. In a two-wheeled caster,the combination of an oscillating wheel-frame swiveled to the attaching or track plate and two anti-friction wheels, one located between the two floorwheels, and the other on an axis in line with the first, on the opposite side of the swiveling center of the caster, as herein set forth.

2. In a two-wheeled caster, the combination, with an oscillating wheel-frame swiveled to the furniture or track plate, of two vertical anti-friction wheels journaled on the wheelframe, one wheel on each side of the vertical plane of the floor-wheel axis, in the same vertical plane with the swiveling center of said frame, and both serving as bearings for oscillation, as set forth.

3. A caster consisting of two floor-wheels, their bearing-frame or housing, a pivot-pin for connecting housing to track-plate, two anti-friction wheels or rollers in line with the pivotal point, and a horizontal connect-ingpin passing through both anti-friction wheels and central pivot, as set forth.

4. In a two-wheeled caster, the combination of the housing having the central bowl or recess, the rocking thimble within the said bowl, anti-friction wheel or wheels, and pivot-pin having ahead held and turning within the said thimble,as and for the purposes set forth.

'5. In a two-wheeled caster, the combination of recessed wheel-housing, rocking thimble within said recess, anti friction wheel or wheels, swivel-pin passing through both thinlble and wheel or wheels, and pivot-pin having a head within said thimble, and serving to unite the caster to the track-platc, as set forth.

M. B. SCHENCK.

Vitnesses:

Gnoncn S. DAVIS, Oims. Giuswom). 

